Data produced by Bloomberg New Energy Finance (BNEF) showed the cost of solar in 58 lower-income countries – including China, Brazil and India – had fallen to about a third of levels in 2010 and was now slightly cheaper than wind energy.

In August, an auction to supply electricity in Chile achieved the record low price of $29.10 (£23.30) per megawatt-hour – a record low price and about half the price of a coal competitor.